The Cystic Fibrosis Foundation awarded up to $4.7 million to EnBiotix Inc. to study the potential use of inhaled colistin to treat chronic Pseudomonas aeruginosa infections in people with cystic fibrosis in the U.S. Pseudomonas infections, which are the third most common lung infection in people with CF, are very difficult to eliminate once established in the airways. 

Although it is approved in Europe, inhaled colistin is not approved for use in the U.S. Currently, the only approved inhaled antibiotics in the U.S. are tobramycin and aztreonam. However, many people with CF find that over time these therapies become less effective at treating their infections. As a result, inhaled colistin is increasingly being prescribed off label.

Additionally, because there are few oral antibiotics that treat Pseudomonas, people with CF often must go on IV antibiotics when they have pulmonary exacerbations, a sudden worsening of respiratory symptoms caused by lung infections. IV antibiotics are problematic because they can cause hearing loss and kidney problems. To prevent future exacerbations, more inhaled antibiotics are required to manage chronic infections.

“New inhaled treatment options for chronic Pseudomonas infections are critically needed,” said JP Clancy, MD, vice president of clinical research at the Cystic Fibrosis Foundation. “Inhaled colistin could provide another drug in the arsenal to help people with CF who are not responding to current treatments.”

The funding would go toward toxicity studies to confirm potentially safe dosages of an inhaled colistin drug that is already approved in Europe. In parallel with these studies, EnBiotix expects to move the drug into Phase 3 clinical trials in the U.S. in 2022.  

Approximately 32% of the nearly 31,000 people with CF in the Cystic Fibrosis Foundation Patient Registry had Pseudomonas infections in 2020, and more than 13% of those infected had multi-drug resistant Pseudomonas infections.